1. Field of the Invention
The present invention relates to a railway vehicular power converter.
2. Description of the Related Art
A power converter is conventionally incorporated in the railway vehicle body of, for example, rolling stock. The power converter is equipped with an inverter and converter for converting an overhead wire power supplied from a pantograph into a predetermined AC power. A railway vehicle drive motor is controlled by this AC power (Japanese Patent Application Publication No. 2004-87711).
Such a conventional power converter is described with reference to FIGS. 11 and 12.
FIG. 11 is a planar cross-sectional view of the conventional power converter. Reference numeral 101 represents a housing (power converter), 102 a power conversion unit, 103 electrical component groups, 104 a blower, and 105 a securing plate.
The housing 101 is in the shape of a rectangular cuboid. The power conversion unit 102 configured by a converter and inverter is disposed in the vicinity of the center of the housing 101. The electrical component groups 103 are disposed at either side surface of the power conversion unit 102 so as to sandwich the power conversion unit 102. The blower 104 is installed at a front surface of the housing 101. The L-shaped securing plate 105 is welded to each of four corners of the housing 101.
Overhead wire power supplied from a pantograph is converted into a predetermined AC power by the power conversion unit 102. Because the power conversion unit 102 generates heat, outside air is introduced from the rear surface side of the housing 101 and released to the front surface side of the housing 101 by the blower 104 to cool the power conversion unit 102 with a forced draft of the air. As will be described hereinafter, the housing 101 is attached to a railway vehicle body by fastening the securing plate 105 by a bolt and the like.
FIG. 12 is a side view of the conventional power converter. In this diagram the housing (power converter) 101 is suspended from the railway vehicle body. Reference numeral 106 represents a bolt, 109 a nut, 107 a bracket, and 108 a railway vehicle body.
The L-shaped bracket 107 is provided at each of four sections under a floor of the railway vehicle body 108 so as to face the securing plate 105 of the housing 101. Each of the brackets 107 and the securing plate 105 are fastened and secured to each other by the bolt 106 and the nut 109. As a result, the housing 101 is suspended under the floor of the railway vehicle body 108.
The conventional vehicular power converter has the following problems.
Because the conventional vehicular power converter is subject to shock due to vibration, the housing (power converter) and the railway vehicle body need to be fixed to each other. However, the housing needs to be small due to the limited space under the floor of a railway vehicle for installing the housing. Moreover, the housing needs to be light due to requests for minimizing labor in maintaining and inspecting the power converter and for improving the workability of maintaining and inspecting the power converter.
However, in the conventional vehicular power converter, in order to increase the strength of a secured section between the housing and the railway vehicle body, a sheet metal for configuring the entire housing including the railway vehicle body and the securing part needs to be thickened, which increases the mass of the entire housing.